SV AP panel mount install
- Thread starter LouRubin
- Start date
This thread has possibly answered a problem I had given up on solving.
When I installed my electric pitch Trim ( a Strong pitch trim system), I tried to control it through the Autopilot panel, but it would not work. I did NOT install TRIMAMPs.
Each time I attempted to calibrate or configure it, it would disable the entire A/P panel, such that the Skyview Network Status would show the panel as offline. To get it online again, I would have to reboot Skyview from scratch and rerun the Network Detect function.
Eventually, I gave up and installed my own relays and bypassed the A/P panel.
However, from reading this thread,, I am now wondering if my Strong pitch trim draws more than 5 AMPS, and that that is why I experienced the A/P panel failure issues.
Does anyon know if the Strong pitch trim motor can draw more than 5 AMPS? The instructions do not mention the amperage, except to say that it requires a 2 AMP cb.
When I installed my electric pitch Trim ( a Strong pitch trim system), I tried to control it through the Autopilot panel, but it would not work. I did NOT install TRIMAMPs.
Each time I attempted to calibrate or configure it, it would disable the entire A/P panel, such that the Skyview Network Status would show the panel as offline. To get it online again, I would have to reboot Skyview from scratch and rerun the Network Detect function.
Eventually, I gave up and installed my own relays and bypassed the A/P panel.
However, from reading this thread,, I am now wondering if my Strong pitch trim draws more than 5 AMPS, and that that is why I experienced the A/P panel failure issues.
Does anyon know if the Strong pitch trim motor can draw more than 5 AMPS? The instructions do not mention the amperage, except to say that it requires a 2 AMP cb.
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Marc_J._Zeitlin
Active Member
I have a "Strong" Pitch trim system in my COZY MKIV. It does NOT draw more than 2A (hence the callout for a 2A breaker in the wiring). I do not have a "TRIMAMP", nor do I need one. If you're using a 2A CB and it doesn't pop when you run your trim, then YOUR trim motor isn't drawing more than 2A either, and the problem is either in the A/P panel or your wiring to it. I'm going to guess that your wiring was incorrect and it was taking the A/P panel down. Another possibility is that the "Strong" system needs to be disassembled and cleaned to reduce friction, but if that were the case I'd expect that it would pop the 2A breaker.
So my $$$ is on whatever wiring you had being incorrect and shorting something out, causing the A/P panel to go offline.
Thanks Marc... FWIW, I did check the wiring thouroughly, and the hat switch would work just fine for 2 or 3 secs before it caused the A/P panel to go offline.
Take a look at attached video...when i saw this is when i kinda gave up trying to diagnose the issue...Video
P.S. I did send the A/P panel back to Dynon, but they bench checked it and said it was 100% operational.
Take a look at attached video...when i saw this is when i kinda gave up trying to diagnose the issue...Video
P.S. I did send the A/P panel back to Dynon, but they bench checked it and said it was 100% operational.
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Marc_J._Zeitlin
Active Member
Charlie, if physically moving the A/P panel causes it to go offline, that's pretty good indication that some connection somewhere is suspect. That doesn't seem to have anything to do with the pitch trim system. Probably/possibly the Skyview network connections.
Marc,
Well, the panel only exhibited this behavior when I had the Strong pitch system wired through the A/P panel. Everything worked fine before that, and after I disconnected the DB-15 connector. I also checked with the DB-15 connector attached to the A/P panel, but disconnected from the Strong motor - Although the pitch trim obviously did not function, the A/ P panel did not drop offline from the Skyview network, and continued to function normally. That strongly suggests to me that something in the Strong system is causing the issue. ... but it works with the relays!
Secondly, watching the video, you'll notice that the panel doesn't just go offline when you move it, it consistently goes offline when it is in or close to the aluminum instrument panel, and comes back online when it is moved away again. I performed this experiment multiple times, moving the panel in different ways, with consistent results, before filming it.. I also noticed that concurrently with the panel dropping offline from the network, the LEVEL button on the panel begins flashing. I'm not sure what that means, except that there must still be power in the panel, it has just stopped communicating with Skyview over the network.
Anyway, no worries, I was just hoping that the 5 AMP/TRIMAMP thing might be another avenue to investigate, but oh well... my next step was to replace the aluminum instrument panel with a composite fiberglass one, on theory that aluminum one is somehow generating an EM field that is somehow affecting the A/P panel, but that is a far-out idea and would take a whole lot of work, so I have been procrastinating, hoping some other idea will occur to me.
Well, the panel only exhibited this behavior when I had the Strong pitch system wired through the A/P panel. Everything worked fine before that, and after I disconnected the DB-15 connector. I also checked with the DB-15 connector attached to the A/P panel, but disconnected from the Strong motor - Although the pitch trim obviously did not function, the A/ P panel did not drop offline from the Skyview network, and continued to function normally. That strongly suggests to me that something in the Strong system is causing the issue. ... but it works with the relays!
Secondly, watching the video, you'll notice that the panel doesn't just go offline when you move it, it consistently goes offline when it is in or close to the aluminum instrument panel, and comes back online when it is moved away again. I performed this experiment multiple times, moving the panel in different ways, with consistent results, before filming it.. I also noticed that concurrently with the panel dropping offline from the network, the LEVEL button on the panel begins flashing. I'm not sure what that means, except that there must still be power in the panel, it has just stopped communicating with Skyview over the network.
Anyway, no worries, I was just hoping that the 5 AMP/TRIMAMP thing might be another avenue to investigate, but oh well... my next step was to replace the aluminum instrument panel with a composite fiberglass one, on theory that aluminum one is somehow generating an EM field that is somehow affecting the A/P panel, but that is a far-out idea and would take a whole lot of work, so I have been procrastinating, hoping some other idea will occur to me.
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Well, thanks, i appreciate your input, but I had this apart and reassembled about six times, replaced all the cables twice, including the network cables, and never saw any indication of wiring issues, but the weird failure of the A/P panel to be recognized by the Skyview network always reoccurred.
Stevec
Member
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- Jun 24, 2020
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- 107
Ok sorry best of luck sorting it out
jakej
Well-Known Member
Just a wild thought here - do you have any 12v to 5v adapters plugged in anywhere on or near the Instrument panel ?
Did you also try turning everything else off, then turn them on 1 at a time, to determine if other avionics/electricals are causing issues ?
Btw, a composite panel is not the solution IMO.
Did you also try turning everything else off, then turn them on 1 at a time, to determine if other avionics/electricals are causing issues ?
Btw, a composite panel is not the solution IMO.
Marc_J._Zeitlin
Active Member
Last response on this topic, because you seem to have already decided that wiring can't be the problem, no matter what the symptoms show, but I'd bet that the issue here is a bad connection in the Skyview network wiring. MOVING the A/P head back and forth causes a disconnect - it's not EMI/RFI interference that's doing that, and certainly not because you have a metal IP. Connecting an electric motor to two wires, when that motor is not activated and has no current flowing through it, is not going to change the connectivity of the A/P head to the rest of the network just because the A/P head is being moved physically.
Good luck with the debugging, if you choose to continue it.
Marc,
I understand your response. Thanks for your input. What I am seeing makes no sense. When I dive into this again, your insistence on the wiring being the issue convinces me to once again recheck all the wiring, including the network wires attached to the A/P head, simply because, as you are saying, nothing else makes any sense.
However, moving the control head back and forth doesn't move the wires on the pitch trim motor end of the db-15 connector to the A/P head, and the head disconnects (electronically), from the network when the wires on that end are connected to the motor, but remains recognized no matter what I do when the wires are not connected to the motor. Also, even when I am not physically moving anything, with the wires all connected, when I would first boot up, the Skyview network detect would find the A/P panel, but if I would try to run the auto pitch trim configuration menu, that would trip the A/P panel offline. And in that process, of course, no physical movement of anything is occurring.
The wiring could be the culprit, however, if it is a wiring issue in the DB15 harness, (going to the hat switch on the stick and to the pitch trim motor). It would make sense that the symptoms would disappear if that connector was disconnected from the motor. That will be my first avenue to investigate if (when) I look at this again.
I only have pitch, not roll trim, and it is only wired to front cockpit hat switch, so my db15 is wired as described on pgs 18-5 through 18-7 of the install manual, using pins 2, 3 7, 8 & 9.
I understand your response. Thanks for your input. What I am seeing makes no sense. When I dive into this again, your insistence on the wiring being the issue convinces me to once again recheck all the wiring, including the network wires attached to the A/P head, simply because, as you are saying, nothing else makes any sense.
However, moving the control head back and forth doesn't move the wires on the pitch trim motor end of the db-15 connector to the A/P head, and the head disconnects (electronically), from the network when the wires on that end are connected to the motor, but remains recognized no matter what I do when the wires are not connected to the motor. Also, even when I am not physically moving anything, with the wires all connected, when I would first boot up, the Skyview network detect would find the A/P panel, but if I would try to run the auto pitch trim configuration menu, that would trip the A/P panel offline. And in that process, of course, no physical movement of anything is occurring.
The wiring could be the culprit, however, if it is a wiring issue in the DB15 harness, (going to the hat switch on the stick and to the pitch trim motor). It would make sense that the symptoms would disappear if that connector was disconnected from the motor. That will be my first avenue to investigate if (when) I look at this again.
I only have pitch, not roll trim, and it is only wired to front cockpit hat switch, so my db15 is wired as described on pgs 18-5 through 18-7 of the install manual, using pins 2, 3 7, 8 & 9.
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Marc_J._Zeitlin
Active Member
So one difference between "trim connected" and "trim not connected" is that when the motor is not connected to the two wires to the A/P head, they are just dangling, and the two pins on the A/P head are effectively not connected to anything. However, when the trim motor is connected (even when off), the two wires are connected to each other through the motor windings in the trim motor. I'm not an electrical engineer, and I have no idea what's going on inside the A/P head, but I can imagine that this could cause a different behavior, if something else was wrong.
One other thought, and one that I've had personal experience with with respect to Dynon telling me that a unit I sent in for examination was 100% OK, is that Dynon (at least at the time, 7 years ago) did NOT do a complete configuration reproduction to replicate the problem I was seeing. In my case, I sent back a D10A, a D100 EMS, and an A/P servo, in sequence, only to have them tell me that each was perfectly fine, but they did NOT set up any of the units with the same connectivity that I had in my plane. Only when connected in the same manner did the problem with one of the units show up, and prove that the unit was NOT 100% OK.
I say this because even though you've sent the A/P head back to Dynon and they SAY it's OK, I'd ask for a loaner unit (or borrow one from a friend), swap it in, and see if the problem reproduces. This would tell you if the issue is the head or something else. Unless they test with the same configuration, WITH a trim motor attached to YOUR unit, they may not be able to detect the problem in the head.
Just another debugging tool...
Marc,
You are correct, and my experience with their techs on the phone has at times (infrequently, I would add), not been entirely awe-inspiring. Although I will check the db-15 wiring again, (carefully), before I consider sending the AP panel back again, I do need to keep that option open in my mind.
As to the swapping idea, as I recall, that did occur to me back when this happened, and I did get Dynon to send me a replacement unit while they were bench testing it, but that unit also exhibited the issues (that's of course no guarantee), but it is highly unlikely that two random units would exhibit the same issue unless it was a design problem, and then all the units in the field would be screwing up. I of course did not send any of the wiring back! (although I did ask Don Jones if he would have his techs check out the installation in my airplane if I flew it up there)... No luck on that
You are correct, and my experience with their techs on the phone has at times (infrequently, I would add), not been entirely awe-inspiring. Although I will check the db-15 wiring again, (carefully), before I consider sending the AP panel back again, I do need to keep that option open in my mind.
As to the swapping idea, as I recall, that did occur to me back when this happened, and I did get Dynon to send me a replacement unit while they were bench testing it, but that unit also exhibited the issues (that's of course no guarantee), but it is highly unlikely that two random units would exhibit the same issue unless it was a design problem, and then all the units in the field would be screwing up. I of course did not send any of the wiring back! (although I did ask Don Jones if he would have his techs check out the installation in my airplane if I flew it up there)... No luck on that
Marc_J._Zeitlin
Active Member
Well, there goes that possibility - as you say, if two units have the same behavior, it's not the head. Which then sends us back to some sort of wiring issue. Can you somehow swap in some OTHER 12V DC motor (some sort of actuator that pulls < 2A), to see if THAT changes the behavior? If it doesn't, then as with the swapped head, it takes the trim motor out of the equation, and we're back to a wiring issue.
Or alien intervention, but I try to use that as a last resort.
CanardMulti
Active Member
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- Apr 1, 2021
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Hi Charlie-
I've been following this thread with great interest, and can feel your frustration.
After seeing your post re the loaner AP head exhibiting *identical* problems to your own AP panel, clearly the situation is either some arcane electromagnetic feedback of some sort from the Strong motor, or the bane of professional avionics techs everywhere, an intermittent harness fault somewhere. I'm inclined to think the latter, but the former is certainly possible.
If it is the latter, it will most likely be something less than obvious and/or unusual. Just some out there possibilities: A broken wire inside an intact insulation jacket? A broken pin that has yet to fall out of the harness DB connector? A slightly corroded pin exterior? Corrosion inside a pin crimp that's just a little bit loose?
If you're inclined to re-double-check the wiring and connectors for faults, I'd suggest building up test plugs duplicating the plugs on the AP panel and checking for proper continuity and no ground faults as you move the test plugs thru the exact same points in space the panel moves when it triggers the fault.
On the trim motor end of things:
If I understood correctly, you say putting relays in between the AP panel wiring and the trim motor eliminates the problem. If so, I'd carefully examine and compare how the trim motor connects to the relays against how the trim motor connects to the wiring coming directly from the AP panel.
Another test: Wire directly from AP panel to motor, but leave the positive motor lead disconnected. Boot everything and watch what happens. Now, still booted, connect the motor lead to the harness while watching the system's reaction. Try the same test but with the positive lead connected and the negative lead initially disconnected. A different reaction might give someone who knows a lot more than me about electronics some food for thought.
One last thought: With disconnected trim motor lines, test the motor w/ a multimeter to see if there's just plain resistance from an armature or some sort of active components inside the motor to maybe reduce noise or to protect the motor. Who knows, if there they might generate feed back that really upsets the AP panel; remember the panel has circuitry to disconnect power after 5 seconds of running the trim. Similar to what was mentioned above, if you can lay your hands on a simple DC motor of similar amp draw, try patching it into the circuit in place of the trim motor and see what happens.
Best of luck and don't let it make you toooo crazy.
Ken
I've been following this thread with great interest, and can feel your frustration.
After seeing your post re the loaner AP head exhibiting *identical* problems to your own AP panel, clearly the situation is either some arcane electromagnetic feedback of some sort from the Strong motor, or the bane of professional avionics techs everywhere, an intermittent harness fault somewhere. I'm inclined to think the latter, but the former is certainly possible.
If it is the latter, it will most likely be something less than obvious and/or unusual. Just some out there possibilities: A broken wire inside an intact insulation jacket? A broken pin that has yet to fall out of the harness DB connector? A slightly corroded pin exterior? Corrosion inside a pin crimp that's just a little bit loose?
If you're inclined to re-double-check the wiring and connectors for faults, I'd suggest building up test plugs duplicating the plugs on the AP panel and checking for proper continuity and no ground faults as you move the test plugs thru the exact same points in space the panel moves when it triggers the fault.
On the trim motor end of things:
If I understood correctly, you say putting relays in between the AP panel wiring and the trim motor eliminates the problem. If so, I'd carefully examine and compare how the trim motor connects to the relays against how the trim motor connects to the wiring coming directly from the AP panel.
Another test: Wire directly from AP panel to motor, but leave the positive motor lead disconnected. Boot everything and watch what happens. Now, still booted, connect the motor lead to the harness while watching the system's reaction. Try the same test but with the positive lead connected and the negative lead initially disconnected. A different reaction might give someone who knows a lot more than me about electronics some food for thought.
One last thought: With disconnected trim motor lines, test the motor w/ a multimeter to see if there's just plain resistance from an armature or some sort of active components inside the motor to maybe reduce noise or to protect the motor. Who knows, if there they might generate feed back that really upsets the AP panel; remember the panel has circuitry to disconnect power after 5 seconds of running the trim. Similar to what was mentioned above, if you can lay your hands on a simple DC motor of similar amp draw, try patching it into the circuit in place of the trim motor and see what happens.
Best of luck and don't let it make you toooo crazy.
Ken
One correction, i did not put relays between the A/P panel and the motor. I just took the A/ P panel out of the pitch trim circuit completely. I put the relays between the hat switch on the stick and the motor, eliminating the functions like auto-trim that the A/P panel provides (I needed the relays to reverse polarity from nose up switch to nose down switch.)
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Rhino
Well-Known Member
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- Jul 20, 2009
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- 1,264
Why not just swap the wires from the switch?